Comparison of Dexmedetomidine and Ketamine in Serratus Anterior Plane Block for Postoperative Pain Control in Thoracotomy Patients: A Randomized Clinical Trial

Postoperative pain control after thoracotomy is very important, and if not controlled, it can cause severe complications.

This study aimed to compare dexmedetomidine and ketamine in serratus anterior plane block (SAPB) in pain control after thoracotomy.

This randomized clinical trial was conducted on 74 patients aged 18 to 60 years old with American Society of Anesthesiologists (ASA) class I or II who were referred to Imam Khomeini hospital in Ahvaz, Iran, for thoracotomy and randomly divided into two groups. After surgery, the SAPB with ultrasound-guided was performed. In the ropivacaine-ketamine (RK) group, ketamine 0.5 mg/kg and 0.4 cc/kg ropivacaine solution 0.25% and in the ropivacaine-dexmedetomidine (RD) group, in addition to 0.4 cc/kg ropivacaine 0.25%, dexmedetomidine 0.5 µg/kg was added. Verbal Numeric Scale (VNS), systolic blood pressure (SBP), diastolic blood pressure (DBP), respiratory rate (RR), heart rate (HR), and mean arterial blood pressure (MAP) were recorded.

There was no significant difference in both groups in terms of demographic information (P < 0.05). The average VNS was lower in the ketamine group than in the dexmedetomidine group; however, there was a significant difference only at 1, 12, and 24 hours after surgery (P < 0.05). There was no statistically significant difference between the two groups in terms of SBP and DBP, HR, and MAP. There was a significant difference in the RR in the two groups at 12 and 24 hours after the operation (P < 0.05).

Dexmedetomidine and ketamine, which were used as supplements to ropivacaine for SAPB in patients undergoing elective thoracotomy, reduced the pain intensity after thoracotomy; nevertheless, the intensity of pain reduction was more and more effective in the group receiving ketamine.